Sync elf.m4 with GCC tree

Sync with GCC
	2015-02-18  Thomas Schwinge  <thomas@codesourcery.com>

	* elf.m4 (ACX_ELF_TARGET_IFELSE): nvptx-*-none isn't ELF.

config/ChangeLog

@@ -1,3 +1,10 @@
+2015-03-16  H.J. Lu  <hongjiu.lu@intel.com>
+
+	Sync with GCC
+	2015-02-18  Thomas Schwinge  <thomas@codesourcery.com>
+
+	* elf.m4 (ACX_ELF_TARGET_IFELSE): nvptx-*-none isn't ELF.
+
 2015-03-16  H.J. Lu  <hongjiu.lu@intel.com>
 
 	Sync with GCC

config/elf.m4

@@ -1,4 +1,4 @@
-dnl Copyright (C) 2010, 2011 Free Software Foundation, Inc.
+dnl Copyright (C) 2010, 2011, 2015 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
@@ -7,6 +7,8 @@ dnl the same distribution terms as the rest of that program.
 
 dnl From Paolo Bonzini.
 
+dnl Is this an ELF target supporting the LTO plugin?
+
 dnl usage: ACX_ELF_TARGET_IFELSE([if-elf], [if-not-elf])
 AC_DEFUN([ACX_ELF_TARGET_IFELSE], [
 AC_REQUIRE([AC_CANONICAL_TARGET])
@@ -15,7 +17,8 @@ target_elf=no
 case $target in
   *-darwin* | *-aix* | *-cygwin* | *-mingw* | *-aout* | *-*coff* | \
   *-msdosdjgpp* | *-vms* | *-wince* | *-*-pe* | \
-  alpha*-dec-osf* | *-interix* | hppa[[12]]*-*-hpux*)
+  alpha*-dec-osf* | *-interix* | hppa[[12]]*-*-hpux* | \
+  nvptx-*-none)
     target_elf=no
     ;;
   *)